1. Field of the Invention
The present invention relates to method of driving an active matrix type liquid crystal display, and more particularly to a method of alternating drive of opposing electrodes in active matrix type liquid crystal displays.
2. Description of the Related Art
An active matrix type liquid crystal display (LCD) comprises a switch element such as a thin film transistor (hereinafter referred to as a “TFT”) in each pixel, and display data is supplied to each pixel electrode via the switch element so that the alignment of liquid crystal in each pixel is controlled by the pixel electrode and an opposing electrode (common electrode) provided to oppose the pixel electrode with the liquid crystal in between.
Although a liquid crystal display inherently has a low power consumption, further reduction in the power consumption is strongly demanded in portable information devices or the like to which LCD displays are equipped, and, consequently, still further reduction in the power consumption of liquid crystal displays is desired.
If the liquid crystal drive voltage which is applied between the pixel electrode and the opposing electrode can be reduced, power consumption can be reduced. However, in order to reliably control the alignment of the liquid crystal, application of sufficient voltage to the liquid crystal is desired, and, thus, the applied voltage to the liquid crystal cannot be reduced significantly. Therefore, in a liquid crystal display, there is a need for some means that can reduce the power consumption without reducing the voltage applied to the liquid crystal and without degrading the display quality and reliability of the device.